textproduct: Quad Cities

KEY MESSAGES

- A warming trend through Thursday followed by a brief cool down, then another warming trend begins over the weekend.

- Thursday afternoon and night is the only time frame that has a chance for rain this week.

- There is a slight (level 2 out of 5) risk for severe storms south of I-80 Thursday afternoon and evening but there is uncertainty regarding the timing of the front and low level moisture.

SHORT TERM /THROUGH TUESDAY/

Issued at 230 PM CDT Mon Mar 23 2026

Cooler than normal conditions will be seen this afternoon and tonight as high pressure moves into the Great Lakes. A passing upper level disturbance will increase clouds tonight with a 5-10% chance of an isolated sprinkle.

Southerly flow on Tuesday will warm temperatures to or slighly above normal. Clouds will be on the increase during the afternoon as yet another weak upper level disturbance approaches from the Plains. The sub-cloud layer is very dry so the chances of an isolated sprinkle occurring are 5-10%.

LONG TERM /TUESDAY NIGHT THROUGH MONDAY/

Issued at 230 PM CDT Mon Mar 23 2026

Tuesday night through Wednesday night Assessment...a certainty (>98%) of temperatures going above normal

Southerly flow will bring warmer temperatures into the area with high temperatures climbing well above normal for Wednesday. Another weak upper level disturbance will move through the area Wednesday afternoon/evening. Like the previous disturbances, the sub-cloud layer is extremely dry so there is only a 5-10% chance of an isolated sprinkle. Attention then turns to Thursday.

Thursday/Thursday night Assessment...high (>80%) confidence of a cold front moving through the area. Low (<25%) confidence on the severe risk and rain chances.

Thursday will be the warmest day of the week, especially ahead of the cold front. Temperatures look to range from around 70 in the Highway 20 corridor to the mid 80s in the far south.

Thursday also looks to be another day of an elevated fire risk, especially south of I-80.

The timing of the cold front will be an important factor regarding high temperatures, fire risk and overall severe risk.

Right now the front is progged by model consensus to arrive in the Highway 20 corridor by late morning with the front around the I-80 corridor by early afternoon. If this timing is correct then the southern half of the area would be at risk for thunderstorms, possibly severe.

However, as mentioned yesterday, a bulk of the moisture for this system will be in the mid and high levels of the atmosphere from the remnants of an atmospheric river. Low level moisture is the key for storm and rain development. There are indications of some low level moisture coming up from the southern Plains which would give some limited low level moisture.

Forecast soundings of the atmosphere clearly show the mid and level level moisture but are still dry in the low levels. Thus the rain and severe risk is a race as to when the 'relatively' more moist low level air arrives. Additionally, the better forcing/lift is along and behind the front. Thus, there may be little if any rain ahead of the front. Condensation pressure deficits quickly rise behind the front suggesting a narrow window of opportunity for rain. Additionally, the extremely dry ground will offer little if any moisture to the boundary layer of the atmosphere.

Based on this there appears to be a narrow window for any rain. An estimate this far out suggests approximately a 6 hour window, roughly 3-4 PM to 10-11 PM as the time frame having the higher probability for rain. The overall severe risk is dependent upon low level moisture. If sufficient low level moisture is present then severe storms are possible.

The model consensus is biased toward the wetter and slower GFS/GEFS solutions which has raised rain chances considerably; 30-40% Thursday afternoon and 20-60% Thursday evening with the higher pops favoring areas south of I-80. The ECMWF/EPS, ICON/ICON-EPS, CMC/GEPS and UKMET/MOGEPS-G are not nearly as moist and would support lower rain chances. The consensus progged QPF is quite low which would also favor lower rain chances. The better rain chance/higher QPF area is east of the Mississippi and south of I-80.

Friday through Sunday night Assessment...very high (>95%) confidence of a brief cool down followed by another warm-up.

Friday/Friday night will be dry, brisk and cool with temperatures averaging below normal. Northerly winds of 15 to 25 mph will add an additional chill.

Southerly return flow develops on Saturday and becomes much stronger on Sunday resulting in another warm-up for the area. The current forecasted winds of 10-20 mph for Sunday look low given the overall pressure gradient across the area. South to southwest winds of 15 to 30 mph would probably be more appropriate.

On Monday things begin to change.

For starters a pattern change will commence that will take several days to complete. However, the end result will be southwest flow aloft developing that will bring another surge of warmer air into the area. The warmer air will be offset by more moisture and clouds.

Moisture will be initially limited on Monday but the model consensus is responding to the developing southwest flow aloft by introducing a 20 percent chance of rain showers in the strong warm advection aloft.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 626 PM CDT Mon Mar 23 2026

VFR conditions will prevail through the TAF period. Winds are currently light and largely variable, owing to high pressure overhead. High pressure will slide east this evening/tonight, leaving us with southeast winds between 5-10 KTs after 12z. No sig wx is expected at this time.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.